Unloading-sling for derricks.



0. CROSBY. UNLOADING .SLING FOR DERRICKS.

APPLlCATlON HLED NOV. 14. 1912.

Patented Apr. 3,1917.

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UNITED r TATFfi NT FFIQE.

OLIVER CROSBY, OF ST. PAUL, MINNESOTA, ASSIGNOR T0 AMERICAN HOIST &DERRICK COMPANY, OF ST. PAUL, MINNESOTA, A CORPORATION OF MINNESOTA.

UNLOADING-SLING FOR DERRIGKS.

Specification of Letters Patent.

Patented Apr. 3, 1917.

Application filed November 14, 1912. Serial No. 731,249.

To all whom it may concern:

Be it known that I, OLIVER CROSBY, a citizen of the United States,residing at St. Paul, Ramsey county, Minnesota, have invented new anduseful Improvements in Unloading-Slings for Derricks, of which thefollowing is a specification.

This invention relates to unloading slings for derricks, etc., andparticularly to the tripping beam or spreader which is suspended fromthe lifting hook of the derrick, and to which the chains of the slingare attached.

The object of the invention is to provide a device of the characterdescribed to which the cane slings may be rapidly and securely attachedand from which they may all be simultaneously released by the operationof a single tripping member to discharge the entire load as a unit.

With the above obj eot in view my invention consists of the constructionhereinafter described and shown in the accompanying drawings, it beingunderstood however that my invention is'not limited to the mechanismshown and described, but that the construction of the same may be widelyvaried without departing from the spirit of my in vention or the scopeof the appended claims.

In the said drawings Figure 1 shows my approved tripping beam in sideelevation, with portions of the sling chains depending therefrom in theposition they assume when the sling is loaded;

Fig. 2 is an end view of the beam looking from the right of Fig. 1; and

Fig. 3 is a detail view partly in section of the tripping mechanismviewed from the Referring now to the drawings, in which like referencecharacters represent like parts throughout the several views, 1indicates the beam proper here shown as consisting of two pieces ofchannel iron riveted together with shouldered rivets as shown in Fig. 2,to provide a space between the channel irons for the reception of thehanger 2 and the tripping mechanism as will belater described. Thehanger 2 is provided with a suitable link 3 for attachment to thederrick cable 4 in the usual manner. The beam shown in the drawing is ofa length to accommodate three sling chains 5, but it will of course beunderstood that a greater or smaller number of chains may be employed ifdesired. At suitable intervals along the under side of the beamdepending hangers or bearings 6 for a shaft 7 are arranged in pairsspaced slightly apart and loosely mounted on the shaft between thebearings are hooks 8 for one end of the chains.

Adjacent each of the hooks 8 is a hook 9 fast to the shaft 7 and soshaped that when the weight of the load comes on the chains, the shaft7, unless prevented by a suitable mechanism will be turned in itsbearings to a position such that the end of the chain slips off thehook. To prevent such rotation of the shaft 7 during the lifting of theload I provide a trip latch 10 mounted to slide vertically between thechannel irons of the beam 1, and held down by a spring 11 in the path ofa dog 12 fastened to the shaft in such a position that when the dog isheld by the latch the hooks 9 are held in position to support the loadas shown by full lines in Fig. 2. The latch 10 is provided with alaterally projecting pin 13, (see Fig. 3), by means of which it may belifted against the tension of the spring 11 to release the dog 12. Foroperating the latch I provide a lever 14. pivotally mounted on asuitable stud between the channel irons of the beam and having its innerend proj ecting under the pin 13. The outer end of the lever 1-1projects beyond the end of the beam and is provided with an eye to whichis attached a rope 15 by means of which the trip may be operated. Theend of the lever 14 is guided between two upwardly projccting guidemembers 16 attached to the end of the beam 1; and a pin 18 is providedat the upper end of the guide members to prevent the lever 14 swingingbeyond its normal operating position. For turning thev shaft 7 to itsoperative position after the latch 10 has been released, I provide ahandle 18 in the projecting end of the shaft adjacent the latch. A stop19, shown in Fig. 2 is also provided to engage the dog 12 and preventexcessive movement of the shaft 7.

In operation the chains, which are provided with a ring at each end, arelaid across the floor of the wagon or car on which the material, forinstance sugar cane, is loaded. When the wagon comes under the derrickat the mill or other unloading point, the tripping beam is lowered to aposition immediately above the load and the rings in the ends of thechains which project from under each side of the load are attached tothe hooks 8 and 9 in the manner shown in full lines on Fig. 2, the shaft7 being locked by the latch 10 in the position 7 shown.- The'derrick isthen'operated to lift the load, and when the load is swung into properposition for unloading the rope I is pulled or jerked by the operatorthereby,

through the medium of the lever 1a and'pin 13, raising the latch 10 fromengagement with the dog 12 and permitting the shaft 7 V to turn underthe weight of the load and release the chains held by the hooks 9. Asthe hooks 8 are loose on the shaft 7fthey are not affected by theoperation of the latch butcontinue to hold the opposite ends of thechains so that as the load drops the derrick draws the chains out fromunderit.

The advantages of my improved tripping V beam Wlll,'1t is thought, beobvious from the ent is:

1. Inan unloading sling, the combination of a beam, means for suspendingthe same from a suitable hoisting mechanism, a shaft extendinglongitudinally of said beam, and a plurality of hooks loosely mounted onsaid shaft, a plurality of hooks attached to said shaft and adjacentsaid loosely mounted hooks, a dog attached to said shaft, a latchengaging said dog to hold said second mentioned hooks in a load-carryingposition and a manually-operated trip for shifting said latch to releasesaid dog, said attached hooks being shaped to free the sling when saidshaft holding means is released.

In a device of the class described, the combination of a beam, a shaftextending longitudinally of said beam, a plurality of hooks looselymounted on said shaft and adapted to support a load when dependingdirectly from said shaft, a plurality of hooks fixed to said shaft, saidhooks being adapted to support a load and shaped to release said loadwhen depending directly from said shaft, means for locking said shaftwith said last mentioned hooks in a load supporting position, and amanually operatable device for releasing said lock.

In witness whereof I have hereunto set my hand at the city of St. Paul,county of Ramsey and State of Minnesota, this sixth day of November,1912.

OLIVER CROSBY.

lVitnesses:

Rosn A. CUMMINGS, OLIVER W. MORTON.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

' Washington, I). G.

